Carburetor for internal-combustion engines



16, 1930. E. PEDRINI CARBURETOR FOR INTERNAL COMBUSTION ENGINES Filed March 14. 1929 Fig.1

Patented 16,1930 y p v 7 045 I anemic rrznnr'nr, or rum, rrnx I OABBURETOB FOB INTERNAL-WTIBUHTION (in Application med rim); 14, 1929; Serial no. 34 7.050, and in. c -mama. m eel-hm; m; is; me.

.This invention relates to'improvements in buretor is provided with an auxilia s ra carburetorsrfor internal combustion engines nozzle for the minimum'engin'e's e w ic the object of which is to effect a preliminar provides for the" reliminary mixing of fuel fuel and alr'mixture before the fuel is a with air as descri din connection, with the l mitted into the suctionpipeas well as'a commain spra nozzle as well as for adjustment pensating actlon on the fuel delivery for the on the fu and air inlet.

purpose of ensuring a practically constant The accompanying drawin shows diacom osition of mixtureat any number of grammatically a constructiona form of the revo utions of the engine. I object of this invention. According to my invention the mixing and Figure 1 is across section of the carburetor. compensating appliances comprise a spray Fi 're 2 is a sectionalview-of a detail on nozzle, whic instead of extending directly anen argedscale; y v into the usual suction pipe ofthe carburetor Referring to'the drawing the carburetor is I ends b adelivery pipe, conical in shape and cast .into apiece comprising the constantlevel rovi ed with one or more circular rows of chamber 1, the conduit 2 for the mains ray oles; this delivery pipe reaches into a suitnozzle and the suction ipe 3 in which a enable chamber having on thesame axis as the turi tube 4 of the usua-Ftype is arranged. spray nozzle other perforated cones and com- The constant level chamber may be of the mumcatin with an outer air intake and with known type and form; in the example shown the top of the spray nozzle in proximity to a float 5 is arrangedin the chamber 1 and is 0 its restricted portion; the chamber 0 ening providedwith.a central boreffor' a needle-6 above into'the main suction pipe of t e carprovided with-a collar 7 to which the usual buretor. e weights 8 are articulated. The cover 9 of the This chamber'and, its air pipes serve for float chamberl is formed with inner rojec-' mixing the fuel delivered by the spray noztions 10 to which the 'abovementione mem zle withair before the fuel reaches the sucbers are connected, and into a'lower .hole of tion pi e where it undergoes a thorough pulthe chamber 1 is screwed a sleeve 11 with a verization, and said chamber in combmation seat 12 'onwhich acts the valve needle 6 and with the pi es communicating wit the outer. op'enings;13 for the fuel which-is conveyed air intake has a compensatingae ion on the to the carburetor through-a pipe connected to 1 delivery of fuel from the spraynozzle which the collar 14 of the connecting tube 11. is automatically exerted when the number v A conduit 2 is branched from the chamber of revolutions of'the engine varies. 1, is threaded at its inner end and connected At low engine speeds the chamber is artthrough a acking 15 with a filter for themain 35 ly filled with liquid fuel so as to-provide a nozzle. T is filter consistsof an outer casing 8| larger evaporating surface in order to allow 16 enclosing a'hollow stem 17 screwed at one for the lower suction and thus gives a mix end on the conduit '2 and carrying at its other ture practically equal to the-normal working end a hexagonal head 18 rovided with abut- 7 mixture. At normal engine speed thecham- ,ments 19 for connecting t e casing 16 tlghtly ber practically contains no fuel and-through to the conduit2. The hollow stem17 has 90 thecommunication with the outer air which transverse holes 20 and a peripheral filter acts directly alsoupon the spray nozzle a fall gauze 21 for the fuel. The outer casln 16 takes place in the under ressure acting on top is further provided with an upper bore exof the spray nozzle wh ch results'in a brak+ tension for conveying the fuel to the mam in action on the fuel delivery and in a poorer spray nozzle 23.

mlxture at high engine speedsin opposition Past its restricted portion the a ray nozzle to the usual carburetors where in suchcase's' 23 is again enlarged to a conica shape and the [mixture is always too rich with an unforms-a distributor 23a provided with holes. necessary consumption offuel. In the example shown th distributor 1! r0- Besides the main spray nozzle my carvided witha lower hole 24, a middle 0 and an upperv row of holes of suitable section and'is threaded on its upper edge for screwing thereon in an adjustable manner a frustrum-shaped cover 26.

The spray nozzle 23 is placed within a chamber 27 that tightly fits on the nozzle at its lower end, is open above and throttled to form a double cone 28 0 posite the holes 25. The chamber is rovide on one side with an adjusted air inta e 29 with which it communicates by a pipe 30 and an opening 31 formed on the throttle ring 28. The air intake 29 also communicates with the hole 24 in the lower portion of the distributor through a pipe 32, a perforated adjusting plug 33 and another pipe 34.

The chamber 1 carries on one side a pipe 37 communicating with a recess 38 cast with the body of the carburetor and communicating through a passage 39 with the suction pipe 3 opposite the throttle valve 40. The recess is screw-threaded above and encloses a tube 41 (Fig. 2) screwed thereon, carrying below an auxiliary spray nozzle 42 for the minimum engine speed and above an air intake 43, both suitably adjusted. Opposite the passage 39 the tube 41 is provided with a'groove 44 having a transversal bore.

This carburetor works as follows: On starting the engine when the number of revolutions is at its lowest, the chamber 27 is partly filled with fuel conyeyed through the conduit 2'from the chamber 1, and through the filter 21, the conduit 22, spray nozzle 23 and hole 35. Upon previous adjustment of the position of the cover 26 with respect to the throttled portion 28, the underpressure acting on the top of the chamber 27 upon an acceleration of the engine, causes the fuel to rise and to come into contact with the air flowing in through the hole 31, suitably mixing with said air. The mixture now immediately enters the suction ipe 3 and re idly empties the chamber 27 and the mixture l urnt by the engine is rapidly enriched and improves the engine acceleration when the number of revolutions vary.

When the engine has reached a normal i. e. a rather high number of revolutions, the chamber 27 is nearly empty and the fuel delivered by the spray nozzle'23 is subdivided through the holes 25 and 35, comes into contact with the air sucked in owing to the underpressure through the adjustedintake 29, mixes with said air and is partly pulverized and conveyed to the Venturi tube'4 already in a finely subdivided state, so that a perfectly uniform gaseous mixture is formed.

At the same time air flows through the hole 24 from the intake 29 and besides cooperating to form the mixture fills the important ofiice of reducing and thus partly compensating the under ressure acting on the top of the chamber 2 with the result of exertin a braking action on the fuel delivery at igh numbers of revolutions of the engine, thereby making the mixture less rich and bringing it to its normal com osition.

By suitabl adjusting the bore 0 the air intake 29, o the openings provided in the distributor 23a and the position of the frustrum-shaped cover 26 a suitable compensation of the mixture is effected at the various numbers of revolutionsof the engine with a considerable economy in the consumption of fuel.

It is clear that in order to improve the mixing action of the chamber 27, one or more suitably perforated cones may be provided in the interior of same, for the purpose of a thorough subdivision of the fuel issuing from the spray nozzle.

The minmium speed appliance also ensures an eflicient preliminary mixing of fuel with air. For this purpose I carefully choose the bore of the spray nozzle 42 and of the air intake 43 of a suitable diameter and the mixture formedtherein is sucked along the passage 39 into the main suction pipe 3 opposite the throttle valve 40.

As the fuel level is above the minimum speed spray nozzle a fuel supply is always stored in the tube 41 for improving starting of the engine.

What I claim is: v

1. A carburetor for internal combustion engines comprising, in combination with a constant level chamber, a spray nozzle and a. Venturi tube, a cone-shaped distributing tube provided with holes at different heights and being an extension of said spray nozzle, a chamber surrounding said distributor and communicating above with the Venturi tube and means for effecting a compensating action on the fuel delivery in order to ensure a practically constant composition of the mixture in the Venturi tube under varying working conditions.

2. A carburetor for internal combustion engines comprising in combination with a constant-level chamber, a spray nozzle and a Venturi tube, a cone-shaped distributing tube provided at its upper end with a circular row of holes, a chamber open at one end and surrounding said distributor, an adjustable cover closing the upper end of said tube and adjusting the annular opening between said chamber and distributor, a throttle ring in the chamber in correspondence with said circular row of holes and means for ensuring a practically constant composition of the mixture in the Venturi tube under varying working conditions.

3. A carburetor for internal combustion engines com rising in combination with a constant leve chamber, a s ray nozzle and a Venturi tube, a cone-shape distributing tube provided at its base with a radial hole and with a radial hole in a middle point and a circular row of radial holes on its upper por-' I said chamber at the level of the circular row of radial holes of the distributor and means for reducing the underpressure in the upper .portion of said chamber during the highspeed working. Y

4. A carburetor for internal combustion engines comprising in combination with a constant level chamber, a s ray nozzle and a Venturi tube,acone-shape distributin tube provided at its base with a radial ho e and with a radial hole in a middle point and a circular row of radial holes on its upper portion, a chamber open at one end and surrounding said distributor, a throttle ring in the chamber at the level of the circular row of radial holes of the distributor, a cover closing the upper end of said distributor and adjusting the annular opening between said throttle ring and the distributor, an ad'usted air intake communicating with sai chamber at the level of the circular row of radial holes of the distributor and a conduit connectin said adjusted air intake with the radia lower hole of said distributor. 5. A carburetor for internal combustion engines comprising in combination with a constant level chamber, a spray nozzle and a Venturi tube, a cone-shaped distributing tube provided with a radial hole at its base, with a radial hole in a middle point and with a circular row of radial holes at its upper portion, a chamber open at one end surrounding said distributor, a-throttle ring in the chamber at the level of the circular row of radial holes of the distributor, a cover closing the upper end of said distributor and ad usting t e annular opening between said throttle ring and the distributor, an adjusted air intake communicating with said chamber at the level of the circular row of radial holes of the distributor, a conduit connecting said adjusted air intake with, the lower radial hole of said distributor and an adjusting plug in said conduit.

6. A carburetor for internal combustion engines comprising in combination with a suction pi a throttle valve, a. Venturi tube in said spray nozzle, a cone-shaped distributing tube provided with a radial hole at its base, a radial hole in an intermediate point and a circular row of radial holes on its upper ortion, a tube open at one end and surrounding said distributor, a throttle ring in the her at the level of the circular row of radial holes of the distributor, a cover closing the upper end of said distributor and adjusting chamthe annular gpening between said throttle ring and the stributor, an adjusted air 1ntake communicating with said chamber atthe level of the circular row of radial holes of the distributor, a conduit connectin said adjusted air intake with the radial ower hole of said distributor, a recess, a conduit connecting said recess constantly with the float chamber, a tube fixed in said recess, a spray nozzle at one end of said tube, an adjusted air intake at the opposite end of said tube and a conduit connecting the tube bore with the suction pipe opposite the throttle valve.

In testimony that I claim the foregoing as my invention, I have si ed mname.

EU NIO EDRINI.

plpe, a constant level chamber, a 

